• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.160-167
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• 1992

The growth of weeds and some other plants has been considered to be inhibited by sicklepod(Cassia tora L.) sharing the habitat. The study was conducted, for the first time, to propose that this phenomenon is not only due to competition for physical and nutritional conditions but also due to allelopathy. In addition, autotoxicity of sicklepod was examined. The results are summarized as follows. 1. Rice sheath length reduced progressively from 18 % to 36 % with increasing the concentration of treating aqueous extracts of sickle pod seeds, but rice germination was not affected. In contrast, radish hypocotyl length was not reduced by the aqueous extract treatment but radish germination was significantly reduced by 66 % at 1 : 10 and 1 : 5 treatment. 2. Total chlorophyll contents in rice seedling decreased from 50 % to 65 % by treatment of seed aqueous extracts diluted from 1 : 50 to 1 : 5 ratio. 3. Aqueous extracts of sicklepod leaves significantly reduced hypocotyl length and fresh weight in radish and germination in rice, but mung bean was slightly affected by aqueous extracts only in fresh weight. 4. Volatiles from fresh, immature seeds with husk reduced the radish germination and seedling growth and radish root growth appeared to be more sensitive to the exposure to volatiles from fresh immature seeds than both germination and hypocotyl growth. 5. Volatiles from sickepod leaves inhibited germination and growth of radish, rice and mung bean, and seedling growth was more sensitive to volatiles from leaves than germination. 6. Volatiles from sicklepod leaves reduced germination and radicle length of sicklepod itself. 7. Collectively, it is concluded that there are water-soluble and volatile substances responsible for allelopathy in sicklepod.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.371-379
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• 2010

Crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa) and rye (Secale cereale) are common leguminous cover crops. Because they contain water-soluble allelopathic substances that show a variable level in tissue depending on growth stage of the plants, the weed inhibition effects are dependent on the growth stage of cover crops. This study investigated the allelopathic effects of crimson clover, hairy vetch and rye on soybean, radish, oilseed rape and lettuce seeds germination and seedling growth. We used extract that were prepared from the shoots of crimson clover, hairy vetch and rye at different growth stages, vegetative growth stage, flowering stage, and fruiting stage. Applications of aqueous extracts from three growth stage of cover crops strongly affected to oilseed rape and lettuce seeds germination but the treatment resulted in a slight inhibition of the germination in soybean and radish. Radical length was more sensitive to aqueous extracts than seed germination rate. Especially, three cover crops extracts at vegetative growth stage highly inhibited seedling root growth of oilseed rape and lettuce by over 80% and 90% respectively. Furthermore, the $GR_{50}$ values were lowest in the treatment of extracts from vegetative growth stage and the level of phenolics was decreased by the order of vegetative growth stage, flowering stage and fruiting stage.

• Korean Journal of Weed Science
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• v.9 no.1
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• pp.28-33
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• 1989

This study was examined for the effect of tuber size, bud and tuber removal, and tuber cutting on growth of Eleockaris kuroguwai Ohwi. Elongation of plumule and radicle, and the weights of tuber, rhizome and shoot were increased as tuber size is large. The weights of shoot and tuber reduced by bud planting without tuber at 15 days after budding, however number of tubers were increased compared with normal tuber. When cross-cutting tubers were seeded, the weights of shoot, rhizome and tuber were produced as 84%, 85%, 71%, respectively compared with normal tuber, and the number of tubers was not influenced. The weights of tuber, rhizome and shoot were lowed as the bud removal, and there were a great number of tubers at bud removal of 15 days after budding. Tuber of E. k, contained as nonfibrous 78.9gr, phosphorous 77mg, iron 16.8mg, niacin 1.3mg per 100gr edble portion. The positive correlations were observed between shoot weight and tuber weight, and number of tubers.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.258-264
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• 1988

Phenolic compounds present in upland weeds (Artemisia asiatica Nakai, Capsella bursa-pastoris (L.) Medik, Portulaca orleracea L. and Trifolium repens L.) which have shown allelopathic activity were determined using paper chromatography (PC) and high performance liquid chromatography (HPLC). Effect of the determined phenolic compounds on germination and post-germination growth of test plants was also investigated. Kinds of phenolic compounds determined by PC in the four weed species were greater in the aqueous extract than in the methanol extract. Ferulic acid was found in both extracts of the weeds studied, whereas benzoic acid was that the weeds commonly contained hydroquinone, p-hydroxybenzoic, ferulic and cinnamic acids. Out of the phenolic compounds determined by PC and HPLC p-hydroxybenzoic, cinnamic and ferulic acids inhibited germination and post-germination growth of radish and sesame. Inhibition of the phenolic compounds on the radicle growth was greater than on the germination of the test plants.

• Journal of Plant Biotechnology
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• v.40 no.3
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• pp.141-146
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• 2013

This study was conducted to examine suspended embryogenic cells growth with days of culture, effects of various kinds/concentrations of osmoticum for induction of somatic embryos (SEs), following somatic embryos germination or plantlet regeneration. The proliferation pattern of embryogenic cells in suspension culture is characterized by settled cells volume (SCV) increased with the duration of culture with marked the maxium of SCV (10.1 ml) in 18 days of culture, however the SCV of cells gradually decreased after that. In comparison of kinds/concentrations of osmoticum on somatic embryo induction, the highest induction number (352.3/g FW) of the SE was showed in 0.2 M sucrose, in addition, we also observed some effects with treatments of 0.2 M maltose (203.7) and 0.3 M maltose (193.7), respectively. However, no somatic embryos produced in treatments of 7.5% PEG plus 0.15 M sucrose or maltose. In comparison of germination efficiency of SEs which occurred from the treatments of various kinds/ concentrations of osmoticum, the highest induction frequency of cotyledon (25.2%) was obtained from SEs that produced 0.3 M maltose, however, the best occurrence rates of hypocotyl (39%), radicle (30.3%) and plantlet regeneration (3.5%) were observed from the 0.2 M sucrose treatment, respectively.

• Applied Microscopy
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• v.41 no.1
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• pp.61-67
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• 2011

The purpose of this study is to investigate the hemp (Cannabis sativa cv. Chungsam) seed structure and ultrastructure of food reserves by scanning and transmission electron microscopy. We examined the seed coat and embryo consisting of a hypocotyl-radicle axis and two cotyledons. The seed coat consisted of exotesta and endotesta. The exotesta was a mechanical layer with lignified and elongated cells, while endotesta of the underlying layers of the exotesta was consisted of two separated cell layers. The collapsed outer layer of endotesta showed the unique reticulate structures. In cotyledon cells, protein and lipid bodies occupied most of cytoplasm. Protein bodies varied in diameter from 1.8 to $5.0{\mu}m$ and possessed a protein matrix containing electron-dense globoid crystals. Numerous lipid bodies ranged from 0.8 to $3.0{\mu}m$ in diameter were distributed around the protein bodies. During the early stages of breakdown, protein bodies rapidly changed their shape into the granular feature, however, lipid bodies were gradually degradated and fused each other. The degeneration process of protein bodies and lipid bodies of cotyledon cells might be correlated with the reports which hemp seeds rapidly lose their ability to germinate.

• Korean Journal of Medicinal Crop Science
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• v.5 no.2
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• pp.154-161
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• 1997

The germination inhibitory effects of American ginseng (Panax quinquefolium Linne) pulp were discussed. The germination inhibitory effects of pulp juice were decreased in a concentration dependent manner. When the pulp juice was diluted 0 (original juice), 1, 2, 5, 10, 20, 50 and 100 times, the radicle lengths of the assay plant, Chinese cabbage (Brassica chinensis Linne), showed 0, 0.32, 0.72, 3.13, 4.83, 16.07, 16.73 and 23.50 mm, respectively (CK=25.98 mm). The pulp evidently inhibited the embryo growth in natural fruit. The longer was the duration that the pulp stayed around the seed, the longer was the time course needed for embryo getting free from the inhibitory effects of pulp. When the depulping was performed on the day 0, 15, 30 and 60 after harvest, the time courses needed for embryo extricating the residual inhibitory effects from pulp were 30, 75, 135 and 135 days, respectively. Moreover, if the pulp stayed around the seed with time, that would make the seed rotten ratio increase. When the pulp stayed around the seed for 0, 15, 30, 60 and 270 days, the seed rotten ratios were 5.47, 5.71, 19.05, 27.14 and 33.33%, respectively. Therefore, we concluded that the pulp could be included in the inhibitory components which made American ginseng seed get into dormancy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.652-665
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• 1997

Allelopathic effects on some crops(rice, barley, wheat, Chinese cabbage, leaf mustard, onion, welsh onion, tobacco, red pepper) for extracts of Phytolacca americana and Armoracia rusticana were investigated in MS solid medium. Germination percentage, radicle length, hypocotyl length, plant height, fresh weight, dry weight, and seedling vigor were rapidly inhibited by methanol extract from Phytolacca americana according to increase of the concentration in test plants. Autotoxicity of Phytolacca americana began to appear at concentrations greater than 50$\mu$l methanol extracts per 20ml medium. The fresh weight and dry weight of Phytolacca americana were also decreased by its own methanol extract according to increase of the concentration. Initial amounts of growth of all crops were also inhibited by methanol extracts from Armoracia rusticana, but the inhibitory effects were lowered than those of methanol extracts of Phytolacca americana. Of four fractions, ethyl acetate, petroleum ether, $1^{st}H_2O, 2^{nd}H_2O$, reextracted from methanol extracts of Phytolacca americana, the ethyl acetate fraction showed the highest allelopathic effects on germination percentage and initial amounts of growth. Chlorophyll contents of rice, barley and Chinese cabbage were more inhibited in the ethyl acetate fraction than in the other fractions. Free proline content of Chinese cabbage was increased 31.2 times in the 100$\mu l$ ethyl acetate fraction, and the contents of rice and barley were also increased according to concentration levels in the ethyl acetate fraction.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.56-62
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• 1985

Effects of butachlor [N-(butoxymethyl)-2-chloro-2', 6'-diethyl acetanilide] and 1,8-naphthalic anhydride (NA) on post-germination growth, mesocotyl and root anatomy and root-cell membrane permeability of rice (Orvza saliva L.) were investigated. Lengths of mesocotyl and radicle were markedly decreased as the application rates of butachlor increased from 0.1 to 100 ppmW and NA from 1 to 100 ppmW, but there was no effect on coleoptile elongation. Application of butachlor-NA resulted in increase in coleoptile elongation, but decrease in mesocotyl elongation. Partial breakdown of cortical cells in root and mesocotyl was caused by either trutachlor or NA treatments, resulting in increase in intercellular air space. Further increase in the intercellular air space of root and mesocotyl was obtained when butachlor was applied in combination with NA. Increase in root-cell membrane permeability occurred when either butachlor or NA was applied. However, butachlor-NA treatments resulted in reduction in the permeability.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.130-138
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• 1987

The effects of light and storage conditions on the germination of Oenothera lamarckiana were investigated. Germination was induced by red light, but inhibited by green, blue or infrared. No germination occurred in the dark. Radicle was more photosensitive than other parts of the seed. The rate of germination was proportional to increase in Light intensity ranging from 10 to 3000 Lux. Photosensitivity occurred 6 hrs after water imbibition of air-dried seeds. Maximum photosensitivity was detected 1-2 days after seeding under the light condition at 300 Lux. Germination was almost completed 3 days after seeding. When seeds stored in the chilling and wetting condition were kept at constant temperature in the dark, they germinated well. Air-dried seeds, however, didn't germinate. Whereas, the seeds which kept at alternating temperature had the tendency that seeds stored at room temperature (25$^{\circ}C$) germinated better than those stored at low temperature (4$^{\circ}C$).